Iridium Browser Install Fatal Error

A
fter installing Iridium Browser, running the program first time I got the following error:

FATAL:zygote_host_impl_linux.cc(124)] No usable sandbox! Update your kernel or see https://chromium.googlesource.com/chromium/src/+/master/docs/linux_suid_sandbox_development.md for more information on developing with the SUID sandbox.

On Debian userns is compiled-in but disabled by default. There's a Debian-specific patch to the kernel that adds sysctl knob: kernel.unprivileged_userns_clone. You have to add a new entry in /etc/sysctl.d and set it to 1